[BUG] Some templates are duplicated during stratification

[liunelson]

1. I start with a simple compartmental model (SCRHD)
   

2. I use stratify to stratify the model by vaccination status u, v but only the variables S, C are stratified

model_vax = stratify(
    model, 
    key = "vaxstatus", 
    strata = ["u", "v"], 
    cartesian_control = True, 
    structure = [],
    concepts_to_stratify = ["S", "C"],
    params_to_stratify = ["a", "vaxCtoH"]
)
model_vax.annotations.name = "SCRHD Vax"

3. Note that two templates (H -> R, H -> D) are duplicated and that should not happen
   
   

Relevant AMR files:

• starting model, scenario2.json
• stratified model, scenario2_vax.json